The interim results showed that 80% of HCV/HIV co-infected patients achieved early treatment success (ETS)*, as defined by the study protocol, when given an investigational HCV regimen that included faldaprevir (BI 201335). Results were consistent across patients regardless of HIV therapy or prior HCV treatment status, including patients who were HCV treatment-naive or had previously relapsed during HCV treatment with pegylated interferon and ribavirin (PegIFN/RBV). Patients who achieved ETS were eligible for randomization to a shortened duration of treatment (24 weeks versus 48 weeks). Investigators also reported on-treatment virologic response at week 12, which showed that 84% of all study patients had undetectable levels of hepatitis C virus.

"Several factors influence the likelihood of treatment success in HCV mono-infected patients, including personal genetic makeup, viral genotype and stage of liver disease. Co-infection with HIV contributes additional factors, including potential drug-drug interactions, that influence treatment decisions and outcomes," said lead study investigator Douglas Dieterich, MD, Professor of Medicine, Liver Diseases at Mount Sinai Medical Center, New York, NY. "The early virologic response data from STARTVerso™ 4 are encouraging, especially given the inclusion of patients with cirrhosis, and we look forward to the final trial outcomes."

The most frequent adverse events (AEs) in STARTVerso™ 4 were nausea (37%), fatigue (33%), diarrhea (27%), headache (23%), and weakness (22%). Serious AEs were reported in 32 patients (10%), including three deaths. To date, 18 patients have discontinued study participation due to AEs. The safety results of this study were comparable to those observed in HCV mono-infected treatment-naive patients in prior faldaprevir clinical studies. No patient on ART experienced a loss of HIV viral suppression during the study period.

In a separate oral presentation at CROI, investigators described the results from three open-label Phase 1 studies in healthy volunteers that evaluated the drug-drug interactions of faldaprevir with the common HIV medications darunavir/ritonavir, efavirenz, or tenofovir. In each of these studies, there was no clinically relevant effect of faldaprevir on the pharmacokinetics of any of the HIV medications studied. However, the respective effects of darunavir/ritonavir and efavirenz on faldaprevir informed the study design of STARTVerso™ 4. Patients already taking darunavir/ritonavir or efavirenz were enrolled into the 120mg and 240mg faldaprevir groups in STARTVerso™ 4, respectively.

These drug-drug interaction findings are part of a comprehensive program to evaluate potential drug interactions of faldaprevir with other medications commonly taken by the diverse patient populations infected with HCV. Most AEs in the drug-drug interaction studies were mild or moderate and all were resolved by the end of the trials. Four healthy volunteers discontinued trial participation due to AEs, including mild or moderate rash, mild elevation in hepatic enzyme levels, or moderate myalgia.

"The interim virologic response rates from STARTVerso™ 4 in HCV/HIV co-infected patients, combined with the drug-drug interaction results of faldaprevir with common HIV medications, are encouraging as we continue toward our goal of developing new HCV treatments for multiple types of patients," said Peter Piliero, MD, vice president, Clinical and Medical Affairs, Boehringer Ingelheim Pharmaceuticals, Inc. "These new data add to our expanding body of clinical evidence on faldaprevir as we continue to pursue HCV treatment options for a diverse range of patients that physicians frequently encounter in clinical practice."

About STARTVerso™ 4

STARTVerso™ 4 is an open-label, sponsor blinded, Phase 3 study assessing the efficacy and safety of Boehringer Ingelheim's investigational oral protease inhibitor faldaprevir in combination with PegIFN/RBV. The study includes 308 individuals co-infected with HCV and HIV who were treatment-naive (TN) or had relapsed after previous HCV therapy with PegIFN/RBV, and were either HIV treatment-naive or being treated with ART. The trial includes patients with cirrhosis (17% had F4 cirrhosis or Fibroscan >13 kPa).

Group 1: 12 or 24 weeks of faldaprevir 240mg once-daily in addition to 24 or 48 weeks of PegIFN/RBV

Group 2: 24 weeks of faldaprevir 120mg once-daily in addition to 24 or 48 weeks of PegIFN/RBV

About Boehringer Ingelheim in Hepatitis C Virus (HCV)

In partnership with the scientific community, our clinical trial program, HCVerso™, is rigorously designed to find answers to the challenges that HCV patients face, including those who are the most difficult to treat.

Faldaprevir, also known as BI 201335, is an investigational, oral protease inhibitor that is specifically designed to target viral replication in the liver. The ongoing multi-study Phase 3 STARTVerso™ trial program, evaluating faldaprevir combined with PegIFN/RBV in treatment-naive, treatment-experienced and HIV co-infected patients with chronic genotype-1 HCV, is near clinical completion. BI 207127 is an investigational NS5B non-nucleoside polymerase inhibitor that has shown the potential to eliminate interferon from HCV treatment when combined in a regimen with faldaprevir and RBV. Phase 2 trials of this interferon-free regimen have been completed and Phase 3 HCVerso™ trials investigating this regimen are now underway.

Faldaprevir and BI 207127 are investigational compounds and not approved by the FDA. Their safety and efficacy have not been established.

Hepatitis C is a blood-born infectious disease and a leading cause of chronic liver disease, transplant and failure that affects as many as 150 million people globally. In the United States, an estimated 4.1 million Americans have been infected with HCV, of which approximately 3.2 million have chronic HCV infection. Since 1999 there has been a significant increase in deaths due to chronic HCV, accounting for 15,000 deaths in the United States in 2007.

About Boehringer Ingelheim Pharmaceuticals, Inc.

Boehringer Ingelheim Pharmaceuticals, Inc., based in Ridgefield, CT, is the largest U.S. subsidiary of Boehringer Ingelheim Corporation (Ridgefield, CT) and a member of the Boehringer Ingelheim group of companies.

The Boehringer Ingelheim group is one of the world's 20 leading pharmaceutical companies. Headquartered in Ingelheim, Germany, it operates globally with 145 affiliates and more than 42,000 employees. Since it was founded in 1885, the family-owned company has been committed to researching, developing, manufacturing and marketing novel products of high therapeutic value for human and veterinary medicine.

As a central element of its culture, Boehringer Ingelheim pledges to act socially responsible. Involvement in social projects, caring for employees and their families, and providing equal opportunities for all employees form the foundation of the global operations. Mutual cooperation and respect as well as environmental protection and sustainability are intrinsic factors in all of Boehringer Ingelheim's endeavors.